A Superior Court judge has refused to release the Norwich Diocese and its former bishop, Daniel P. Reilly, from potential liability for alleged sexual abuse by a priest, in a strongly worded ruling that could represent a legal sea change in how such cases are handled.

The ruling by Judge Jonathan Silbert runs counter to a long line of precedents, but Silbert said that recent revelations about the scope of the church's sex scandal justify the departure.

The diocese maintains that any priest who sexually assaults a minor has "abandoned" the employer's business. Nearly half a dozen cases, including a 1995 ruling by U.S. District Judge Alfred V. Covello, have adopted this theory and released the church and its leaders from liability.

"The number of reported allegations of sexual assaults by priests has risen so dramatically that one must wonder whether Judge Covello, and particularly those judges who followed [his ruling], would be so quick to conclude that there could not possibly be a factual dispute over whether such molestation could take place within the scope of a priest's employment," Silbert wrote.

Silbert denied the church's motion to strike an element of Michael Nelligan's lawsuit alleging the diocese and Reilly knew of former priest Bruno Primavera's propensity for sexually abusing minors and should be held liable for his conduct.

Silbert stressed that "a contemporary court cannot ignore" findings of a national study released last month by the U.S. Conference of Catholic Bishops that, between 1950 and 2002, 4,392 priests - or 4 percent of the clergy - had sexual abuse allegations lodged against them.

"Assuming that these reports are accurate, they would suggest the addition of facts that were not available to those judges who have been confronted with this issue in the past," Silbert wrote. "This court, at least, is not prepared to conclude that an activity which might be undertaken by as many as 4 percent of an employer's employees is a clear-cut `digression from duty' as a matter of law."

Silbert's ruling permits Nelligan's lawsuit to move forward. Nelligan alleges that Primavera sexually abused him at St. Mark the Evangelist Church in Westbrook in 1977 and 1978, when Nelligan was 15 and an altar boy. Primavera later was transferred to St. Mary's Church in New London, where he is alleged to have assaulted another boy, who has filed suit under the pseudonym of John L. Doe. Both are represented by attorney Robert I. Reardon Jr. of New London, who also represents other victims of alleged sexual abuse by priests.

Reardon said that much of the case law shielding the church from liability was written by "judges who had no appreciation of the widespread problem that existed."

"The whole environment has changed dramatically over the last few years," Reardon said. "Now we know this problem was rampant throughout the Catholic Church, and that certainly affects the way judges are viewing these cases.

Reilly is now bishop of the Worcester Diocese. Attorney Joseph Sweeney, who represents the Norwich Diocese and Reilly in the case, wrote off Silbert's decision as a preliminary ruling on a very technical issue.

"It's really no big deal," said Sweeney. "I except no problem prevailing on this issue. I just have to go the long route rather than take a shortcut."

"It's fundamental law," Sweeney said. "When a Catholic priest molests a child, he is betraying the very principles for which the Catholic religion stands, and is clearly outside the scope of his employment."

Primavera was sentenced to serve four years in prison for assaulting boys in New Mexico, where he had been sent for treatment.

Silbert acknowledged that further evidence in the case might well establish that the alleged activity by Primavera "is definitely beyond the scope of a priest's employment," but that decision should be made after a full airing of the facts. But he noted that the court, "which certainly cannot accept that notion as a matter of faith, is also in no position to accept it as a matter of law."